Concentration of ores



I ment. This collective concentration may advantageously cfl'ected crude ore or s milar mix ast s, s, 1925.

UNITED Io Drawing.

STATES mum's ,To all whom it mayconccm:

, Be it known that I,

Cnannns KENNETH 'MOARTHUR, Jr., a subject ofthe King of GreatBritain, residing at Butte, 1n the county of Silver 7 Bow, State of Montana,

have invented certain new and useful Improvements in the Concentration of- Ores;

and I do hereby declare the following to be a full, clear, and exact description ofthe invention, such as will enable others skilled in the art to which it use the same.

appertains to make and This invention relates tothe conceiitration of ores or mineral s b flotation, and

more particularly to the di erential separation by flotation of sulfide mixed sulfide product such minerals in "a for example, as

a mixed sulfide flotation concentrate The invention has for its obfject the provislon of an improved method 0 differentially separating by floatation different minerals in a mixed I sulfide product.

. the invention aims to provid method of separating by More particularly, e an improved differential flotation difierent sulfide minerals in a mixed sulfide product containing oil' or a similar flotation agent, such, for example, as a mixed sulfide flotation concentrate.

Complex or mixed trates and the like,

sulfide ores, concensuch, for example, as amixed sulfide product carrying sulfides of lead and/or copper.

and/orsilver together with sulfides of'zincand/or iron, present diflicult I problems cei-ncd with, the

sulfide minerals therein.

to the metallurgist conseparation of the different,

I have found that in the differential treatment of man mixed Sulfide ores and other mixed sulfi e ucts, it is advantageous to subject the ore or product to a preliminary collective p crude concentration to-separate the sulphidesfrom the gangue prior to the difierentialtreatto a flotation operation tially all ofithe sulfide m in the resulting concentrate. The mixed sulfide flotation concentrate tainedcarries with it a the oil or other flotation the flotation-operation, that such oil or other fl cises a deleterious. or i be subjecting the sulfide in which substaninerals are removed collective certain amount of agent employed in and I have found otation agent exernhibitory influence m'rnua, an, or 311mm, coucm'raanon or ones.- Application and m a, 1m. Serial in. 711,473.

product thus ob PATENTJOFFICEI IOMANA.

n the subsequent diflerential separation u o the different sulfide minerals in the collective mixed sulphide concentrate. articularly contem- My present invention plates an improved met 0d of diflerentially separating by flotation different .sulfide min erals in such a rough concentrate, or in similar mixed sulfide products containing agents or substances, such as oil on, other flotation agents, which exercise difi'erentia'lflotation-inhibitory influences. Thus, the ins reduced to a desired difierentialflotation operation is overcomeor appropriately reduced; 7 a

n carrying out my present invention, I make use of the selective action of cyanides such, for example, as sodium cyanide in inhibitin the flotation of. certain 'sulfl e minerals uch as zinc and/or iron sulfides) while fide and/or silver sulfides). In the difierential treatment of oiled concentrates and other permitting the flotation of mixed sulfide products containing substances otatlve properties, theselective action .nlde-must be supplemented by treatment of the mixed sulfide modifying the deleterious or p fluence of. the oil or other difi'erentialota-.

possewing fl I have dis covered that ofthe cyaother sul minerals (such aslead and/or'copper pp oh t l rod'u ct'zgoribito 1ntion-inhibitory substance. I have found that very satisfactory sub wt-in'f' fi the oiled concentrate, or similar mixed su de product, to the action of a suitable cyanide 1n conjunction with a hydrox ide, preferably a readil soluble suchassodium hydroxi ment the mixed sulfides to differential separation by flotation.

The treatment of-the mixed sulfide prodhydroxide, efafter which treatare readily amenable results are obtained 'by' uct with a c .anide and a hydroxide, inac-.

cordance wit erably a time treatment, that is to say, the

my present invention, is pref-.1

mixed sulfide product is subjected to the actionof a cyanide and the invention accomplishes two primary results, to wit 1) a physical and/or chemical change in the oil (or other flotation agent) present in the mixed sulfide product wherey the deleterious or inhibitory influence of the oil (or other flotation agent) in the subsequent difi'erential flotation operation is overcome or appropriately reduced, and (2) a selective action upon the sulfide minerals sulfides) is whereby the flotation of one or more (for example, zinc or iron sulfides) is in large measure inhibited, while the flotation of one or more (for example, lead, copper or silver ermitted or evenpromoted.

" In thepractlce of the invention, I have found that the combination of a cyanide and a hydroxide generally gives the most satisfactory results, but I have also ascer tained that the hydroxide may be in part, or even entirely, replaced by other substances ca able of reacting as bases with the oil or ot er flotation agent present in the mixed sulfide concentrate or product. Thus, I have found that an alkali cyanide when used alone in sufiiciently large'amount serves not only to bring about the desired selective action but also the necessary" conditionmg or change in the characteristics of the oil or other flotation agent. When an alkali cyanide is thus used alone, the amount required for the purposes of the present invention is substantially in excess of that required for effecting diflerential separation by flotation of the same sulfide minerals in the absence of the oil or other flotation agent. And similarly, where the .hydroxide is replaced in whole or in part by other substances capable of reacting as bases with the oil or other flotation agent in the mixed sulfide concentrate or product, the amount of such basic reagent required for the purposes of the present invention is substantially in excess of that required in conjunction with the cyanide for effecting satisfactory differential separation by flotation of the same sulfide minerals in the absence of the oil or other flotation agent.

The amount of cyanide and hydroxide to be employed in practicing the present invention. varies with different mixed sulfide products. In general, satisfactoryresults can be obtained by the use of from 0.5 to 5 product and from 2 to 15 pounds of sodium hydroxide per ton of dry product. In the treatment of a silver-lead-zinc-iro'n rough flotation concentrate, I have obtained excellent results using 6 pounds of sodium hydroxide and from 1.5 to 3 pounds of sodium cyanide. per ton of dry concentrate. In the subsequent difierential flotation operation, following the treatment of the mixed sulfide product with cyanide and hydroxide, lead,

copper and silver sulfides will be found readily amenable to flotation and are recovered in the resulting froth, while the zinc and iron sulfides remain in large extent in the tailings or residue. In the treatment of oiled flotation concentrates, the differential flotation operation can generally be conducted without adding any flotation agent to the pulp. .If desired, or necessary, however, an

pounds of sodium cyanide per ton of dry appropriate flotation agent for promoting into an'appropriate container provided with suitable mixing instrumentalities. A cyanide alone or a hydroxide and a cyanide as the case may be and in suflicient quantities to condition the oil in the concentrate and to bring about the desired selective action between the dilferent sulfide minerals is added to the container, or to the concentrate before the introduction of the concentrate into the container. The amount of the hydroxide and/or cyanide may be varied to meet any conditions of the concentrate that may arise. Thorough mixing for a period of about thirty minutes should preferably take place. The so-treated mixed sulfide product is then conducted to appropriate flotation apparatus, in which the differential flotation operation takesplace. As hereinbefore stated, the oil present in the collective mixed sulfide concentrate, perhaps'enhanced as a flotation agent by its conditioning for the purposes of the present invention, generally provides ample flotation agent for the differential flotation operation. It will, however, be understood that appropriate flotation agents may be added to the pulp, if dey sired, for the differential flotation operation.

The practice of th invention will be further illustrated by 't e following exam les:

1) 2000 grs. of a mixed or. combin tation product, with a density of 35% solids, assaying 14.8 ozs. Ag., 4.6% Pb., 56.8% Zn., and 2.3% Fe., was placed ina square glass mixing jar, mechanically driven, with an amount of sodium cyanide equivalent to five (5.0) pounds per ton of product, and sub ected a time treatment of thirty minutes. The product was thenre- 26.4% Zn., and 3.6% Fe'., and a residue assaying 12.0 ozs. Ag, 1.0% Pb., 60.0% Zn., and 2.1% Fe. was made. (2) 2000 grs. of a mixed or combined flotation product, with a density of %solids,

. I lent to two and two tenths- (-2.2) poun l0 tonof dry product, and subjected to 8.1311110 assaying 17.0 ozs. Ag, 6.0% Pb., 55.0% Zn.,

" and 3.1% Fe, was placed in a square glass mixing jar, mechanically driven, with 'anamount of ,sodium' hydroxide equivalent .to

seven and five tenths (7 .5.) pounds per ton of dry product, and sodium cyanide eguivas er treatment of thirty- (30) minutes. The

' product was then removed from the jar, and

without the addition of further reagents, 'placedin a Callow laboratory flotatiorrmachine'wherea float assaying45.0 ozs.

residue assaying 12.0 ozs. Ag, 0.5% Pb., 60.0% Zn., and 3.0% Fe, was made. l'claimzj 1. A process of differentially separating by flotation difierent sulfide minerals, which comprises treating'a, flotation reagent-contially reduces the d ifierential-flotation-inhibitory influence of the 'flota'tion reagent pre'sentin said-product and thereby effecting a marked difference in'the amenab-ilit to flo-, tation between two difl'erent sulfi e m1n-.

' by flotation difl'erent sulfide minerals, which comprises, treating a flotation reagent-contaminatedcollectively floated mixed sulfide product with a cyanide and a basic hydroxide and thereby effecting a marked difference in' the amenability to flotation between two different sulfide minerals in said product, and subjecting the so-treated prodnet to a flotation operation whereby the flotationof one sulfidemineral is in large part effected while the flotation of anothersulfide mineral-is in large part inhibited.

'3. A process of differentially separatin by flotation difi'erent sulfide minerals, whic comprises treating a flotation reagent-contamina'ted collectively floated mixed sulfide product with a cyanide and an appropriate basic agent caipable of substantiall Y ducing the di erentia rel -flotatio n-inhi itory i inhibited. 60.0% Pb'., 14.0% Zn., (12.4% Fe., an a .by flotation leadand iron 3 comprises treating a flotation reagent-con-1 influenceof the flotation reagent present in sald product and thereby efi'ectin a marked tween two different sulfide minerals in said product, and subjecting the so-treated prod-' uct to a flotation operation whereby the flotation of one sulfide mineral is in large part effected while the flotation of another sulfide mineral is in large part inhibited.

4.. A process of difl'erentiallyseparating by flotation difi'erent sulfide minerals, whic comprises subjecting a collectivelyv floated mixed sulfide product contaminated with a flotation reagent to the action of a basic hydroxide and thereby; reducingv to a' deflotation reagent upon the subsequent differential flotation operation, and subjecting the so-treated mixed sulfide product in the,

form of a pulp to -a differential flotation operation in the' presence pr 9. cyanide w erebythe flotation of one, sulfide mineral is in large part effected whilethe flotation ofanother sulfide mineral is in large part 5. A process of difi'erentiall separating by .flotationglead and 'zinc su fides, which f comprises tr'eatin' a flotation-reagent-contaminated collectively floated mixed lead. and zinc sulfide product with a cyanide and an agent capable of substantially reducing the difierentla'l flotation-inhibitory influence taminated collectively floated sulfide product with acyanide and an agent which substanof "the 'flotation reagent present .in said difference in the amenabilityto otation be-' '80 sired extent the inhibitory influence of said 1 product and thereby effecting a marked difierence in the a'menability to flotation be tween the lead and zinc sulfides, and subjecting-the so-treated product toa flotation operation whereby the flotation of the lead sulfide is in. large part efl'ected while the flotation of the zinc sulfide is in large part inhibited. v

6. A- process of des, which tamlna'ted collectively floated mixed lead and 5difli'erentiall separating iron -sulfide product with a cyanide and an V agent capable of substantially reducing the dflferentlal-flotation inhibitory influence of.

a marked difier'ence in the amenability to the flotationr age Pr s n Said Pmduci "Q and iron sulfides,*and vsubjectilin;:the sotreated product to a flotation. operation whereby the flotation ofthe' lead sulfide is in large part efl'ected while the'flotati'on of,

the iron sulfide is in large part inhibited.

7. A process of differentially separatin comprises treating a flotation reagent-contamlnated collectively floatedmixed copper andiron sulfide productwith a ,cyanide and an agent capable of substantially. reducing the differential-flotation-inhibitory influence offtheflotaticn reagentpresent in saidprodnot and thereby efiectin'g a marked difierby flotation-copper andironsulfideawhic ence in the amenability to flotation between the copper and iron sulfide, and sub ecting the so-treated product to a flotation operation whereby the flotation of the copper sulfide is in large part effected while the flota tion of the iron sulfide is in large part 1nhibited.

8. A process of differentially separating by flotation copper and sulfides, which comprises treating a flotation reagent-contaminated collectively floated mixed copper and zinc sulfide product with a cyanide and an agent ca able of substantially reducing the difl'erentlal-flotation-inhibitory influence of the flotation reagent present in said product and thereby effecting a marked difference in the amenability to flotation between the copper and zinc sulfides, and subjecting the so-treated product to a flotation operation whereby the flotation of the copper sulfide is in large part effected while the flotation of the zinc sulfide is in large part inhibited.

9. A process of differentially separating by flotation silver and iron sulfides, which comprises treating a flotation reagent-contaminated collectively floated mixed silver and iron sulfide product with a cyanideand an agent capable of substantially reducing the difl'erential-flotation-inhibitory influence of the flotation rea ent present in said roduct and thereby e ecting a marked difference in the amenability to flotation between the silver and iron sulfides, and subjecting the so-treated product to a flotation operation whereby the flotation of the silver sulfide is in large part effected while the flotation of the iron sulfide is in large part inhibited.

10. A process of differentially separating by flotation silver and zinc sulfides, which comprises treating a flotation reagent-contammated collectively floated mixed silver and zinc sulfide product with a cyanide and an agent capable of substantially reducing the diflerential-flotation-inhibitory influence of the flotation reagent present in said product and thereby effecting a marked difference in the amenability to flotation between the silver and zinc sulfides, and subjecting the so-treated roduct to a flotation operation whereby tii fide is in large part effected while the flotation of the zinc sulfide is in large part ,inhibited.

11. A process of differentially separatin by flotation lead, copper and silver sulfides from zinc sulfide, which comprises treating a flotation reagent-contaminated collectively floated mixed lead, copper, silver and zinc sulfide product with a cyanide and an a entcapable of substantially reducing the diflerential-flotation-inhibitory influence of' the flotation reagent present in said product ands thereby effectipg a marked difiere flotation of the silver sul-=' tannnated ence in the amenability to flotation between the lead, copper and silver sulfides and the zinc. sulfide, and subjecting the so-treated product to a flotation operation whereby the flotation of the lead, copper and silver sulfides is in large part effected while the flotation of the zinc sulfide is in large part inhibited.

12. A rocess of differentially separatin by flotation different sulfide minerals whic comprises treating a flotation reagent-contammated collectively floated mixed sulfide product containing lead sulfide product with a cyanide and a basic hydroxlde and thereby efl'ecting a. marked difference in the amenability to flotation between the lead sulfide and another sulfide mineral in said product, and subjecting the so-treated product to a flotation o eratlonwhereby the flotation of the lead su fide is in large part effected while the flotation of another sulfide mineral is in large part inhibited.

13. A process of differentially separatin by flotation different sulfide minerals whic comprises treating a flotation reagent-com taminated collectively floated mixed sulfide product containingzinc sulfide roduct with a cyanide and a basic hydroxi e and thereby effecting a marked difference in the amenability to flotation between the zinc sulfide and another sulfide mineral in said product, and subjecting the so-treated product to a flotation operation whereby the flotation of one sulfide mineral is in large part effected while the flotation of the zinc sulfide is in large part inhibited.

14. A process of differentially separatin by flotation different sulfide minerals which comprises treating a flotation reagent-0ontaminated collectively floated mixed sulfide product containing copper sulfide product with a cyanide and a basic hydroxide and thereby effecting amenability to flotation between the copper sulfide and another sulfide mineral in said product, and subjecting the so-treated product to a flotation operation whereby the flotation of the copper sulfide is in large art effected while the flotation of another a fide mineral is in large part inhibited. N

15. A process of differentially se arating by flotation different sulfide mineral; which a marked difference in the a comprises treating a flotation reagent-con- A product containing silver sulfide product g with a cyanide and a basic hydroxide and collectively floated mixed sulfide process of'diflerentially separating tammated collectively floated mixed sulfide product containing iron sulfide product with a cyanide and a basic h dioxide and thereby efl'ecting a marked difi rence in the amenability to flotation between the iron sulfide and another sulfide mineral in said product, and subjecting the so-treated product to a flotation operation whereby the flotation of one sulfide mineral is in large part efl'ected while the'flotation of the large part inhibited.

. 17. A rocess of differentially se arating by flotatlon different sulfideminera which comprises treating a mixed sulfide product containing an oily substance which exercises difierential flotation inhibitory influences with a cyanide and an agent which substantially reduces the difl'erential-flotation-in- I hibitory influence of the oily substance present in said groduct and thereby efl'ecting a marked di erence in the amenability to iron sulfide is in flotation between two different sulfide minerals in said product, and subjecting the sotreated product to a flotation operation whereby the flotation of one sulfide mineral is in large part eflected while the flotation of another sulfide inhibited.

18. A process of difl'erentially se rat' by flotation different sulfide minerafi whi d comprises treating a mixed sulfide product containing an oily substance which. exercises difierential flotation inhibitory influences with a cyanide and a basic h droxide and thereby effecting a marked ,di erence in the amenability to flotation between two difierent sulfide minerals in said product, and subjecting the so-treated product to a flotation operation whereby the flotation of one sulfide mineral is in large part eifected while the flotation of another sulfide mineral is in large part inhibited. y

In testimony whereof I afiix my signature.

CHARLES KENNETH IcARTIIUR, Jr.

mineral is in large part 

